What it means
A can of worms is a messy situation that looks small at first, then the second you start digging, loads of extra problems crawl out. One question turns into side arguments, awkward facts, blame flying about, and suddenly the whole thing's kicking off.
Usage examples
"I asked why the budget didn’t match the receipts and opened a can of worms. Now everyone’s arguing in the group chat and Finance wants a meeting."
"Asking who broke it opened a whole can of worms about who does the chores."
"Auditing one invoice turned into a can of worms across the entire department."
"Don't ask why Sharon left the committee unless you've got snacks and free time, mate. That's a whole can of worms."
"We only wanted to fix the rota, then it turned into a can of worms about pay, favouritism, and who hasn't done a proper shift in months."
Where it comes from
It comes from literal cans or tins of worms sold as fishing bait. Open one up and you've got wriggling chaos that's hard to control or pack away neatly again. By the early 20th century, that image had shifted into the idiom for starting a problem that quickly spills into a bigger mess.
